Introduction

To evaluate the impact of PSMA PET (prostate specific membrane antigen positron emission tomography) findings prior to salvage radiotherapy (SRT) in recurrent prostate cancer (PCa) after radical prostatectomy (RP) on metastasis-free survival (MFS).

Patients and methods

Between 01/2012 and 12/2018, 1,599 patients received SRT for biochemical recurrence after RP at our institution. Five-year MFS of “positive PSMA PET” (n = 49) vs. “negative PSMA PET” (n = 106) vs. “no PSMA PET” (n = 1,599) prior to SRT was determined. For all time to event analyses, uni- and multivariable Cox's proportional hazards models and univariable Kaplan-Meier analyses were applied, with a significance threshold of P < 0.05. Further 4:1 propensity score matching for patient, cancer and treatment characteristics was performed to account for residual differences between groups.

Results

Of PSMA PET patients, 106 patients exhibited “negative PSMA PET” (68.4%) and 49 exhibited “positive PSMA PET” (31.6%). Median PSA at recurrence did not differ between groups (0.2 ng/ml; P= 0.4). After 4:1 propensity score matching, 5-year MFS between “no PSMA PET” and “negative PSMA PET” was 94.4 vs. 93.0%, respectively (P = 0.8). For “no PSMA PET” versus “positive PSMA PET”, 5-year MFS was significantly lower in “positive PSMA PET” (92.3 vs. 48.5%, respectively P < 0.0001). Finally, “positive PSMA PET” was independently associated with worse MFS compared to “no PSMA PET” after multivariable adjustment in the overall cohort (HR 13.8, CI 7.5–25.2, P < 0.001).

Conclusions

Locoregional positive PSMA PET findings in recurrent patients after RP are highly predictive of worse MFS in the setting of SRT.

中文翻译：

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PSMA PET 预测根治性前列腺切除术后挽救性放射治疗的无转移生存期

介绍

评估 PSMA PET（前列腺特异性膜抗原正电子发射断层扫描）结果在根治性前列腺切除术 (RP) 后复发性前列腺癌 (PCa) 中的挽救性放疗 (SRT) 之前对无转移生存期 (MFS) 的影响。

患者和方法

在 2012 年 1 月至 2018 年 12 月期间，1,599 名患者在我们机构接受了 RP 后生化复发的 SRT。确定了 SRT 前“阳性 PSMA PET”（ n  = 49）与“阴性 PSMA PET”（n  = 106）与“无 PSMA PET”（n  = 1,599）的五年 MFS 。对于所有事件发生时间分析，应用单变量和多变量 Cox 比例风险模型和单变量 Kaplan-Meier 分析，显着性阈值为P < 0.05。对患者、癌症和治疗特征进行了进一步的 4:1 倾向评分匹配，以解释组间的残余差异。

结果

在 PSMA PET 患者中，106 名患者表现出“PSMA PET 阴性”（68.4%），49 名患者表现出“PSMA PET 阳性”（31.6%）。复发时的中位 PSA 在各组之间没有差异（0.2 ng/ml；P = 0.4）。经过 4:1 的倾向评分匹配后，“无 PSMA PET”和“阴性 PSMA PET”之间的 5 年 MFS 分别为 94.4 和 93.0%（P  = 0.8）。对于“无 PSMA PET”与“阳性 PSMA PET”，“阳性 PSMA PET”的 5 年 MFS 显着降低（分别为 92.3 和 48.5%，P < 0.0001）。最后，在整个队列中进行多变量调整后，与“无 PSMA PET”相比，“阳性 PSMA PET”与更差的 MFS 独立相关（HR 13.8，CI 7.5-25.2，P < 0.001）。

结论

RP 后复发患者的局部区域阳性 PSMA PET 发现高度预测 SRT 环境中更差的 MFS。